We have now had Tilly Mint for just over a month and she is turning into quite a character ! Think we are on top of the feeding (she came to us on a diet of fruit and lettuce) and she now enjoys various weeds and flowers.We bathe her every day and she is fairly active when she is awake ( between 10am ish - 4pm ish!)

My question is this - How often should she wee and poo?

About a week after having her there were a few days when there was a whitish powdery substance in her bath which i assumed was wee but have seen nothing for over a week now. And I think I have only ever seen one poo in her table.

She has a shallow water dish in her table which we change every day so she always has access to fresh water

If your tortoise has had poor treatment before you got her, she could well have been dehydrated and had an empty gut. It takes approx a month for an adult tortoise to fill its gut properly, so less likely to see poop in this time. Tortoises are not like us in that they don't urinate daily. They can hold on to urine for months to prevent dehydration as water is not readily available for them. In a house situation this can be dangerous as humidity is naturally much lower indoors. How old is she, I'm assuming young as you mention a table? Soak her every few days in shallow water, even when offering water, as the powdery stuff is a sign of dehydration. When the white stuff is liquid it's fine, but not powdery or solid. It's waste uric acid, so not exactly urine, but a separate substance. Do you have pics of her, preferably a side view and an underneath shot will help with ID. Well done for taking her on ;)

We were told she is about 14 months (hatched early August 2014) - I have weighed and measured her - she is 7cm and 83kg which i believe is bigger than you would expect for her age - I'm guessing from what I have read, that this is due to poor diet and rapid growth which seems to have resulted in slight pyramiding